Crank window part
It sounds like your operator gears are stripped out, which will necessitate total replacement of the operator in question. We can help, but I will need to see a clear photo of it removed from the window entirely.
Any idea how the plate / cover comes off to expose the mechanism?
I can't seem to force it off. Thanks!
Yep, the gears are definitely stripped. You will need an all new operator.
Odds are the cover cannot be removed in your case. Older operators like this were designed so that the "cover" is permanently affixed to the base. That wouldn't help, anyway; we need to see the entire mechanism out of the window in order to match it up.
This photo is perfect, honestly. There are a few key details on display here that tell me exactly what I need. This operator appears to be an older version of our 39-221B. Coincidentally, this newer version's cover and handle are sold separately under our 39-451 kit and are fully detachable.
I'm pretty confident these are the parts you want, but you should look over them carefully just to see for yourself. Let me know if you had any questions or doubts.